“Black powder” is a term used to describe the appearance of a material that is found in hydrocarbon pipelines (for example, natural gas pipelines) and other pipelines. The material is sometimes wet either from water or liquid hydrocarbons. The solids include a mechanical mixture or chemical combinations of iron sulfides, iron oxides, dirt, sand, salts, chlorides, water, glycols, hydrocarbons, compressor oils, mill scale, or other materials. Black powder can be caused by bacterial and chemical corrosion of a carbon steel pipeline wall. Moisture can act as a catalyst that creates the corrosion resulting in production of iron sulfides and iron oxides in different forms. Black powder sometimes consists of magnetite (iron oxide) and can also include components such as manganese (Mn) and magnesium (Mg).
Black powder is a common problem affecting hydrocarbon pipelines world-wide. Black powder is an extremely hard abrasive material, which can cause erosion of the pipeline wall, seize valves, and damage meters. Black powder can also damage compressors and turbine components. In liquid transmission pipelines, black powder can sometimes cause pump failure.